The invention relates to a rotor for a turbo engine, in particular a gas turbine.
According to the state of the art, a distinction is made in principle between two types of rotors for a turbo engine, namely so-called integrally bladed rotors and rotors in which the blades are inserted, i.e., anchored, in a rotor base body by a footing.
Integrally bladed rotors are referred to either as BLISK (bladed disk) or BLING (bladed ring), depending on whether the rotor base body is disk-shaped or ring-shaped. In such integrally bladed rotors, the rotor blades are fixedly connected to the ring-shaped or disk-shaped rotor base body and thus form an integral part of the rotor base body. Production of such integrally bladed rotors is complex and may be performed, for example, by milling from a solid on a 5-axis milling machine. One disadvantage of integrally bladed rotors in a BLING or BLISK design is the poor possibility of repairing them.
Rotors in which the rotor blades are inserted into the rotor base body via footing are easier to manufacture and repair than integrally bladed rotors but they are much heavier than integrally bladed rotors because the connection of the rotor blades to the rotor base body by way of the blade footing is under high stresses due to centrifugal forces and therefore must be designed with a reliable construction. In the related art, the rotor base body is designed in the shape of a disk in rotor designs in which the rotor blades are anchored in the rotor base body via the footing. The disk-shaped design of the rotor base body and the connection of the rotor blades to the rotor base body via suitably dimensioned blade feet results in a heavy weight of the rotor, which is a disadvantage of this design principle.
Against this background, the object of the present invention is to propose a novel rotor for a turbo engine, in particular for a gas turbine.
According to this invention, the rotor base body is formed by at least one ring-shaped element made of a metal matrix composite material (MMC material), where the rotor blades are attached to the rotor base body by footing so that the footing is positioned in a fiber-free area of the rotor base body.
In the sense of the present invention, a rotor for a turbo engine is proposed, preferably having a low weight on the one hand while being easy to manufacture and repair on the other hand. Thus, in the sense of the present invention, the rotor base body is formed from at least one ring-shaped element made of a metal matrix composite material. The design of the rotor base body has at least one ring-shaped element and, manufacturing it by the MMC technology, allows a definite weight reduction in comparison with the rotors known from the related art. In addition, individual rotor blades can be replaced easily when repairing the rotor.
According to an advantageous refinement of the present invention, the rotor base body is comprised of two ring-shaped elements made of a metal matrix composite material (MMC material), the rotor blades being attached between the two ring-shaped elements on the outer end radially. Blade feet of the rotor blades engage in a corresponding recess, i.e., indentation in the area of the ring-shaped elements, namely between fiber-reinforced areas of the two ring-shaped elements. Each rotor blade is preferably positioned with one platform each between peripheral protrusions of the two ring-shaped elements that are on the outside radially, with the ends of the platforms being in contact with the peripheral protrusions.
According to an alternative advantageous embodiment of the present invention, the rotor base body is formed by a ring-shaped element made of a metal matrix composite material (MMC material), sections of the ring-shaped element on the outside axially being fiber-reinforced and a section in between being designed to be fiber-free, with the blade footing of the rotor blades being secured in the fiber-free section. Boreholes running radially are preferably created in the fiber-free section of the ring-shaped element, each rotor blade being anchored by footing in a borehole.